Workpieces, including food products, are portioned or otherwise cut into smaller pieces by processors in accordance with customer needs. It is usually highly desirable to portion and trim the workpieces into uniform sizes, for example, for steaks to be served at restaurants or chicken fillets used in frozen dinners or in chicken burgers. Much of the portioning of workpieces, in particular food products is now carried out with the use of high-speed portioning machines. These machines often use various scanning techniques to ascertain the size and shape of the food product as it is being advanced on a moving conveyor. This information is analyzed with the aid of a computer to determine how to most efficiently portion the food product into optimum sizes. For example, a customer may desire chicken breast portions in two different weight sizes. The chicken breast is scanned as it moves on an infeed conveyor belt and a determination is made through the use of a computer as to how best to portion the chicken breast to the weights desired by the customer, so as to use the chicken breast most effectively.
One example of a high-speed portioning machine uses rotary or reciprocating blades to portion horizontal workpieces as they move along a conveyor assembly. More specifically, the portioning machine includes an infeed conveyor that transitions into an outfeed conveyor along the same longitudinal conveyor line. A transverse gap is defined between the interior infeed conveyor belt nose and the interior outfeed conveyor belt nose that is sized to allow a rotary blade to pass thereto. As the horizontal workpiece moves from the infeed conveyor to the outfeed conveyor, the rotary blade passes through the gap at a high speed to cut the workpiece.
The blade can be adjusted so that it passes vertically through the horizontal workpiece, or it can be angled to where it passes through the workpiece at a substantial angle, for example, at forty-five degrees (45°) relative to the horizontal conveyor belts. In each instance, it is desirable to keep the gap small so that the workpiece is well supported by the conveyors as the blade passes therethrough. More specifically, when the blade is passing vertically through the workpiece, it is desirable to have the interior outfeed conveyor belt nose level with or slightly lower than the interior infeed conveyor belt nose. When the blade is passing through the workpiece at an angle, the gap can be minimized by dropping the interior outfeed conveyor belt nose lower than the interior infeed conveyor belt nose while also moving the interior outfeed conveyor belt nose longitudinally (e.g., horizontally) toward the interior infeed conveyor belt nose. In both instances, the blade is substantially tangent to the infeed and outfeed conveyor belts defining the gap.
To date, adjustment of the conveyor belt positions and the blade angle has been done manually and in series. As can be appreciated, numerous attempts are typically required to accurately set the infeed to outfeed conveyor belt gap to match the blade position. Moreover, an operator must lock and tag all power sources of the machine, remove equipment guarding, and then try to adjust and properly position the belts in an area that is wet, messy and difficult to access and see. The operator may not know if the belt is in the proper position until he re-assembles the machine, re-applies power, and runs several pieces to check the accuracy of his adjustment. If it is incorrect, he must repeat the process until it is correct. This is all done in a typically cold, hygiene-conscious food processing environment. Even in an ideal environment, the infeed to outfeed conveyor belt gap adjustment process is unreliable and prone to human error. If the belts are not properly positioned relative to one another, the blade could hit one of the belts, causing damage to the machine, or the workpiece may not be properly portioned or otherwise damaged. This conveyor belt gap adjustment process is also time consuming and therefore increases the downtime of the machine. With typical machines operating at two to three hundred finished pieces per minute or higher, even minutes of downtime leads to significant loss of revenue.
These issues are sought to be addressed by the automatic blade and conveyor gap adjustment assemblies discussed below.